Africa-Press – Uganda. As the government steps up plans to bring in different types of Covid-19 vaccines for immunising the population, researchers have said new evidence shows that mixing vaccines gives stronger protection against the disease and new variants.The government opted to import different types of vaccines because of hardship in securing sufficient supplies from the manufacturers of AstraZeneca (AZ) vaccine.
Countries such as China and the African Union are giving more options by either donating a different type of Covid-19 vaccine or are connecting the country to buy vaccines from different sources. A study published on June 25 by the University of Oxford, the developer of the AZ vaccine, after giving a dose of AZ followed by Pfizer vaccine four weeks apart to 830 volunteers aged 50 and above, triggered a stronger immune response in recipients than giving two doses of AZ. In the study report, giving AZ followed by Pfizer also induced higher immune responses than Pfizer followed by AZ.The study report is not yet peer-reviewed. It is titled ‘Safety and Immunogenicity Report from the Com-COV Study – a Single-Blind Randomised Non-Inferiority Trial Comparing Heterologous And Homologous Prime-Boost Schedules with An Adenoviral Vectored and mRNA COVID-19 Vaccine’Commenting on the report yesterday, Dr Misaki Wayengera, an immunologist and the head of Government Scientific Advisory Committee on Covid-19, said the increased protection after mixing AZ and Pfizer will be a likely scenario with other vaccines.
The country plans to bring 300,000 doses of Sinovac from China and unspecified number of Johnson & Johnson doses and also vaccines from Cuba, among others, according to information from the government. “The good protection observed after mixing AstraZeneca and Pfizer will be a likely scenario with other vaccines,” Dr Misaki said.
Dr Bruce Kirenga, the director of Makerere University Lung Institute, who is treating Covid-19 patients at Mulago National Referral Hospital, said: “[This is a] landmark finding; mixing vaccines will soon become a reality in many settings.”Up to 854,443 people in the country have so far been vaccinated with AZ and by June 18, only about 57,000 had received the two doses.
The country recently received additional 175,200 doses of AZ, which have been rolled out for the second round. The doses are not enough for more than 700,000, who are either due or nearing the time for second dose, which has been capped by the government at three months after the first dose.Since the outbreak of Covid-19 last year, the country has registered 79,434 cases of infections, 989 deaths and 52,382 recoveries, according to government statistics.
